Low power Adaptive Viterbi Decoder with Section Error Identification

Abstract

As mobile communication devices have evolved rapidly in our daily life, the power consumption becomes a very important issue. The channel decoders of mobile devices play a key role in transmitting information over the noisy wireless channel. Viterbi is one of the most popular error correcting channel decoders in many wireless communication devices. However, the Viterbi decoder also consumes a lot of power of portable and wireless devices, especially the Survivor Memory Unit (SMU) of decoder. In this paper, a low power adaptive Viterbi decoder with section error identification method is proposed to reduce the dynamical power consumption in varying channel noisy. We use error detecting method to identify whether the segment of the received codeword sequence is erroneous. We can disable Viterbi decoder with clock gating technique to save power consumption when finding a correct data section by error detecting method. The SMU has been split into several segments based on the truncation length of SMU for low power purpose. Subsequently, each segment of SMU can be disabled dynamically according to the instant status of error-detecting in noisy channel environment. Furthermore, we also shorten the truncation length of SMU using Path Metric Comparison Unit (PMCU) to select the optimal decoding results for achieving more dynamical power saving. With the techniques mentioned above, experimental results show that the proposed method has more than 20% power saving compared with the traditional Viterbi decoder.